Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites

TL;DR

This paper investigates how the Dzyaloshinskii-Moriya interaction (DMI) underpins the coexistence of ferroelectricity and incommensurate magnetism in multiferroic perovskites, supported by simulations and phase diagram analysis.

Contribution

It demonstrates that DMI is the microscopic mechanism for multiferroicity in RMnO3, with phase diagrams matching experimental observations.

Findings

Multiferroic phase exists between A and E antiferromagnetic phases.

Phase diagram aligns with experimental data.

DMI is key to ferroelectric-magnetic coupling.

Abstract

With the perovskite multiferroic RMnO3 (R = Gd, Tb, Dy) as guidance, we argue that the Dzyaloshinskii-Moriya interaction (DMI) provides the microscopic mechanism for the coexistence and strong coupling between ferroelectricity and incommensurate magnetism. We use Monte-Carlo simulations and zero temperature exact calculations to study a model incorporating the double-exchange, superexchange, Jahn-Teller and DMI terms. The phase diagram contains a multiferroic phase between A and E antiferromagnetic phases, in excellent agreement with experiments.